Process of and apparatus for rolling tubes, solid round bars, and similar bodies.



B.. C. STIEFEL.

Mousse. 0F AND APPARATUS A0A ROLLING mums, soun Roman BARS, AAD SIMILARBODIES. APPLIOATIN FILED MAY 20, 1008. TFA AUA 9 W AMA u Amante@ aA. 1l,ww.

3 BHEETB-BHEET 1.

u., STIEFEL PROCESS `0F AND APPARATUS FOR ROLLING TUBES, SOLH) Hmmm ARS,AND SIMILAR'BODIES. K APILIOATION FILED MAYBE, 1906.

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. l l 1 A R. C. STIEFEL. PROCESS 0F AND APPARATUS FOR ROLLING TUBES,SOLID ROUND BARS, AND SIMILAR BODIES'.

` APPLIoATroN funn MAY ze, 190s.

Patented Marl 0.

3 SHEETS-B -3.

'PROCESS OF AND APPARATUS RALPH CHARLES STIEFEL, OF ELLWOOD CITY,PENNSYLVANIA.

rou. ROLLING TUBES, SOLID nonno BARS, AND SIMILAR nomas.

anonce.

v Specication of Letters Patent.

Patented Mar. 1, 191e.

Appncation'mea may 26,1909. serial mi. 435,042.

To all 'whom it may concern:

le it known that l, RALPH CHARLES- STIEFEL, a citizen of the UnitedStates,'re siding at Ellwood City, Pennsylvania, have invented certainnew and useful Improve'- ments in Processes of and Apparatus for tube orbody durin to-lw longitudinally of thebodyl t.

.Rollin Tubes, Solid Round Bars, and Similar Bo ies,'of which thefollowing is a specification, illustrated by drawings.

The invention is particularly useful for rolling and elongatlng tubesand tubular blanks .of iron or steel in a heated state upon mandrels toelongate the tubes and reduce the wall thickness; or with the omissionof the mandrel it isfalso applicable to therolling of solid round bodiesto elongate and re- 'pince their diameters.

"lt is also applicable to any metal that will stand the treatment.l

By a description of the invention in the preferred' torni as applied tothe rolling of tubular bodies upon mandrels, its adaptability to solidbodies will be well under-l stood without further explanation.

The invention contemplates the application of' rolling pressure on thesides of' the its continuous passage through a pass an while in contactwith rolls by which the pressure is applied.

' ln the preferred form of the invention the application of the actingforces is suchthat each successive cross section of the body is firstcompressed between surfaces that `crossroll it while confining thepressure within' narrow limits circumerentially', allowing and causingthc-metal to How circumferentiall'y while the body is being fed forwardinto the pass; then, as it pro esses, each section. is subjected tolongitu inal'rolling while 'being confined and ,under pressurecircumferentially 'through a -large proportion of the circumference,causingfthe netal an to consequently ,elongate and reduce then, eachsection as .it progresses farther is subjected to a smoothingcross-rolling action between parallell or approximately parallel faces,which permit or cause the metal to flow circumferentially to insure itssubstantial'lyncylindrical shape as it issues from thepass.`-v

ln the-drawings, Figure 1 is an elevation of two rolls for elfecting theimproved proc `ess, as seen 'omlthe .exit end of the ass:

1 is a diagram explanatory of Flg. l

and Fig. 1b a similar diagram of a variation. Fig. 2 is a centrallongitudinal section of the same. Fig. 3 is a horlzontal section throughthe axis ofthe. pass. Fi 4 is a vertical section across the inlet en ofthe pass at approximately the irst points ofcontact be tween the tubeillustrated and the rolls. Figs. 5, 6, and 7 are end view, longitudinalsection, and 'horizontal section, of amodiica-4 tion, the rolls beingslightly skewed. Fig. 8 shows a inodi'cationrhaving three sets of rollsacting eonjointly, in which a combined as well as separate etl'ect uponthemetal will'be produced by the three sets, as hereinafterexplained.Figs. 9 and 10 are. central longitud'inal section and horizontal sectionof the axis of a pass to illustrate another modification. Fig. 11illustrates another modifica` tion.

'llhe details of the bearings,l housings, mechanical adjustments andwell known flexible driving connections for the rolls are notillustrated, assuch details do not concern the process of treatment.given to the metal or the combination of the rolls themselves, and asconnections for driving adjustable shafts with axes set as shown arewell known. :Tubular blanks and mandrels are; shown, but the mndrels arbof course` omitted. when treating `solid bod-ies. Guides1 for guidingthe work/into the pass 'and out of it, as used-'in practice, are also`omitted as they explain the new invention. f Two rolls shown in Figs.1,4 2, 3, and 41, have rollin symmetrica ly placed in respect to eachother and. the axis of the pass. The axes of the rolls are parallel witheach other and, as illustrated, are horizontal, lying in a common planeperpendicularl to the axis. of the pass.

A is the lower roll and Atthe upper roll., B, B and C, C are the axes ofthe roll and H H the axis of the pass; D is the mandrel; E thetubular""blank or billet; F andfGpV are thejourna-ls or shaft extensionof, the rolls.

surfaces of similar shapes and are not novel with or necessary to Eachroll has a flange presenting a plane i From theplane surface i .throughbetween the rolls under the most perfect conditions, but some latitudein size .by a s light approaching or separation of the,

rolls 1s of course contemplated. 'It will be seen that at the crosssection through the pass shown in Fig. l, which is in the plane of thetwo axes of the rolls, the metal is confined and radially compressed bythe rolls through a large portion of its circumference by the curvedHsurface between the point O andP of the roll A in Fig. l and the similaropposite surface of the roll A. From' P to Q, the roll may be straightand tangentialjof the curve O P, being therefore truly cylindrical soasgradually to leave the body E as seen in Fig. 1. Instead of thecylindrical ortion P Q, a concave surface as seen in IEig. 1", at P Qmay be substituted so as to somewhat further embrace, com ress and connethe metal at the mid e of the pass, the radius of curvature of thesurface indicated by these dotted lines beingmuch greater than H O inorder that the end or edge of the rolling .surface shall not cut intothe body that is being rolled.

The billet or tubular blank E, if of iron, steel, or similar metal at atemperature suitable for hot rolling the metal, is placed upon themandrel D,lwhich is preferably cold, and is introduced .through suitableguides into the inlet end of the ass. The blank ybeing of slightlylarger ra ms than the H O (Fig. la) will first make contact with the tworolls at two opposite points where the l blank first meets theconverging surfaces L of motion of the flange of the upper roll A- atthe point 1 (Fig. 2) of rst contact is forwar and downward, as indicatedby the line 1-4 in Fig. 2, while that of the lower roll is upward andforward, as indicated by the line 1-3. The forward feedin components ofthe effects of the two ro ls are equal and are indicated by the line 15, as The rotating 'or cross rolling/effect of the two rolls at thepoints 1 of the pass is roughly indicated by the oppositely directedcomponents of motion v5 3 and 5 4, but being on opposite sides of thebody or blank, they both .tend to produce rotation in the samedirection; right-handedly as seen in Fig. 4. As the cross sectionof thebillet enters farther into the pass,- this gripping and` cross rolling,

pressure by the flanges on opposite sidesof the blanklncreasesprogresslvely in amount and in the width ofthe area of contact betweenthe blank and the opposing flanges until and after the section reaches apoint where the roll surfaces M act to compress the blank horizontally,diagonally, and also verticall on opposite sides (see Fig. 2). When t egiven cross section reaches the transverse plane of the axes of therolls, as at 7 in Fig. 2, the confining and rolling pressure extendscircumferentially around two areas including more than half the totaleriphery of the blank, as seen in Fig. 1.

ut at this cross section the motions of all points of the rolls incontact with the billet are longitudinally forward parallel with theaxis of the pass. There is no cross rolling component.

A third stage of the procedure is reached as the given cross section ofthe billet, passing out from the most connedcross section of the pass,emerges toward the exit end of the pass and the rolls again make.contact with the billet only on narrow lines at opposite sides wherethe flanges of the roll still remain in contact with the blank. The lastpoints of contact between the rolls and the blank are approximatelylocated at the` points marked A8 1n Figs. Q'and 3; and at these pointsit cross rolling pressure on the surface of the 9 blank but in thedirection that tends to rotate or twist the blank in a direction reverseto the tendency at the inlet end of the pass. y The surfaces N of theroll flanges at the exit will produce a smoothing effect tending to rollout and smooth away any bunching or crowding of the metal at oppositesides of the billet Vproduced in the previous portions of the pass, andwhich is shown in cross section of the blank E in Fig. 1.

Having thus followed the procedure ap plied to any one cross section ofthe blank, it will be seen that a simultaneous action is occurrin at theinlet and exit ends of the pass on iferent sections or portions of thesame blank whereby at the inlet end the metalv is bein cross rolled byforces ap- 'plied to a limited area of the surface at opposite points,as in Fig. 4, and the metal v subjected to a right-handed twistingtendency; at the exit" end ofthe pass the .metal is subjected to areverse rotary or .twisting tendency and iven a smoothing action; and atan interme iate cross section longitudinal rolling compression of themetal occurs between surfaces that contne the metal circumferentially\around the greater part of the eri hery. At the inlet of the ass the PP P metal'wlll flow mostly circumferentially of the'billet, as forexample along the line WW of Fi 4; while at the middle portions of thepass t e metal is necessarily elongated and is prevented -frommaterially enlarging radially; It is vconsequently reduced in externaldiameter and thickness. At the exit end of tate at equal speed, andtheaxial feed com-l ponents are approximately equal `at -alfl'other pointsof vthe Ipassm` The cross rolling component of motion of the rollsdiminishes and again increases in reverse direction as the axialdistance from the transverse plane Z,

Z through the central :point 7 of the pass varies. y

I prefer to have ythe forces at work upon the lank symmetrical, that vitto say balanced at diametrically opposite :points of the blank as itadvances "throu h the pass; 4and this is 'the case in the application ofthe invention that I have fjust described. As lthe billet advances into=the inlet side of the.

pass, it is lirst subjected to a cross rolling and pressure 'by what Imay call point contactor narrow line contact *between blank and roll.Subsequently itis subjected to an embracing surface contact andpressure, compelling the metal to yield longitudinally; and .lastly itis subjected to cross rollingfor smoothingv between opposedandsubstantially plane parallel surfaces.

Itwill be 'seenthat the action to which I subject the rblank differsradically from the.

common procedure 'of rolling out bars lor tubes between rolls havingsemi-circular or semi-elliptical grooves and that it differs equally`from the well known art of piercing or expanding billets or tubes bycross rolling between rolls by which the blank is not embracedcircumferentially 'through any considerable portion of its periphery atany one instant.

In Figs. 5, 6, and 7 rolls with axes slightly oblique to each other andto the transverse plane ont the 'pass areshown for carrying out the'process.

In Figs 1 to 4 inclusive the blank after coming in contact with theflange portions of the rolls haste travel -a considerable distancebefore it is embraced circumferentially to any` great extent; and duringthis period of its'progress it is subjected to torsional or twistingstrain. In 'cases where `metals having less resistance to such strainsthan iron and steel are to be treated; or where the ythinness ofthe wallor other conditions make a diminished torsional strain preferable at.the entrance to the pass, this can vbe accomplished by disposing theroll axes slightly incline'dtoward the rear of the pass, las shown inFigs. 5, 6, and 7 ,making the con-verging entrance of the -pass 4moreessonne abrupt (as will be 'clear from Fig. 7,) as

more prolonged straight sided exit end of the pass. The rotary -ortwisting effcct of theexit Will dominate when the reduction .of diametergiven to the blank is but slight.

It Vwill be understood by those familiar with this art that my process,even in the entire absence of any cross-rolling effect at the entranceoity the pass prior to the longitudinal rolling and circumferentialpressure, is characterized in the preferred forms described by acontinuous progression and transmission from longitudinal rolling andcircumferential compression to a substantially simple cross-rollingaction without circumferential compression, and all in a single pass. V

In cases Where very large reductions of wall thickness or externaldiameter are required, I Vprefer to accomplish the total rcduction bysuccessive repetitions of the process that I have Iso far4 described.This may be done by several sets of rolls as eX- cmplified in Fig. 8. Iprefer to place the succeeding pairs of rolls so near the precedinglpairs that the blank and mandrel bar will comel within the grip of thelast pair of rolls before leaving the rst pair, and to proportion thespeeds of the succeeding pairsl of rolls to compensate forthe elongationrof the metal which-occurs in each pair of rolls, the succeeding pairsoperating faster in proportion to the reduction of cross section of theblank that occurs.` Obviously, however,

.as a mandrel bar, which is preferably in a cold state, can only assumeone forward speed for all its points, its speedwill be less than the'feeding speed of they third or lastpair of rolls andgreater than thefirstpair of rolls. By this use -of my process, therefore, I produce alongitudinal movement between the mandrel and the tubular blank. Thisalso facilitates the 'removal of the tube from the mandrel bar afterthey leave the roll.

The process may be also utilized with a mandrel thatish'eld stationaryso far as endwise movement is concerned but is free to rotate. This isillustrated in Figs. 9 and 10,

wherein a short mandrel or plug U is shown on the end of a bar T whichis braced against Va fixed support S, allowing the mandrel U 4i ao,

only extends through-the middle and rear portions of the pass does nottend to reduce or prevent the somewhat dierent speed of rotation andconsequent twist of the billet at the commencement of the pass where itis `first gripped by the roll flanges, as heretofore explained.Incidentally the rotation of the mandrelu causes it to wear more evenlyon all sides, and to remain round much longer producing consequently asmoother'surface on the interior of the tube than if the mandrel did notrotate. I l The process may be 'also used to give-very slight reductionin thickness of the walls of the tubes where it is only desirable toreniove creases or irregularities such as are frequently produced intubular blanks by the ordinary methodv of rollin a tubular blank over astationary mandr or. plug. Similarly the method may be employed formerely rollingv A out rou'gh places on the outside surfaces of thetubes, such as are frequently produced in billets-'thathave beenApiercedor rolled by defective or rough rolls or mandrels or injured by scale.In utiliing .the process for this purpose I prefer to mmnnize thelpressure and reduction occurring at the middle of the pass where themetal is confined circumferentially and to rely mainly on the last stepof the process where the cross rolling action mainly occurs. A

If the rolls already described are 'drawn slightly farther apartvertically, that-is perpendicularly to their axes, the circumferentialconfning action will be lessened `or omitted while the cross rolling inreverse directions at the inlet and exit ends of the pass remains. Whereit is desired to cross roll or reel a tube to compress it very slightly,so as toA remove creases or rough places inside or outside the first andlast stages of the process or the last stage only ma be employedexclusively, thecentral portion of the passvacting merely as rotatingguides for the tube 'I and mandrel, holding them in alinement in thecenterl of the pass, while the wall of the tube is compressed and rolledspirally forward'between the flanged portions of the rolls.V Such guidescan be made to lit the tube much closer vwithout practical inconvenienceand ifthe tube tends to'bind between the`guides they at once act to rollit longitudinally forward insteadlof opposing it`as/ wquld-.xed guidesvor idler rollers.

In F1g.,1l the rolls are shown with the curved portion corresponding toO P in Fig` 1a transformed into cylindrical and plane faces. Such rollscan embrace and confine the metal on four sides at the center ,of thepass or, when adjusted so that the horizontal dimension of thepass isless than the vertical, can.only cross roll the blank' between theopposed `anges.

It will be seen that in the various figuresrolls overlap the cooperatingflange of the opposed roll to produce the rotatory or twisting tendencyon the body being treated. It will also be seen that the rolls rotateapproximately in opposite directions when their axes are inclined andexactly in opposite directions when their axes are parallel, as commonin grooved rolls for longitudinal rolling. y

It will be clear to those skilled in the rollin art that the dimensionsof either of a palr of rolls may be increased relatively to the opposingroll and the angular speed proportionately decreased without materiallyaltering the surface speed and equal effects of the two rolls.

Without attempting to set forth many other modifications, I claim anddesire to secure b Iietters Patent the following:

I. lbe improvement in theart of rolling tubes or round bodies, whichconsists in subjecting such a body to a continuous and progressiverolling and l compressive pressureA while moving forward in a suitable'pass by pressing and cross rolling the body in the inlet end of thepass between approximately parallel rolling faces, thereb tending torotate the bod while allowmg the metal to ow circum erentially,simultaneously subjecting the cross sections of the body farther withinthe pass to confining `and rolling pressure'around a large part of itsvperiphery from surfaces moving substan- 'tial y longitudinally of thepasswith little or no cross rolling motion', whereby the metal flows andelongates in an axial direction and simultaneously subjecting the crosssections of the body in the exit portionof the p'ass to rolling pressurebetween approximately plane surfaces moving transversely to the pass'and tending to rptate the body reversely to the inletportions of theass, for substantially the purposes set fort 2. The improvement in theart of rollingl tubes or round bodies, which consists in subjecting sucha body to a Acontinuous and progressive rolling and compressive pressureWhile moving forward in a suitable pass by subjecting the cross sections'of thefbody to confining and rolling pressure around a large part ofits erlphery from surfaces moving substantial y longitudinally of thepass with little or no cross rolling motion, whereby the metal flows andelon ates in an axial direction and simultaneous y subjecting the crosssections of the body inthe exit portion 4of the same pass to rollinpressure between approximately plane sur aces mov- `ing transversely tothe ass and tending t rotate the body, for su stantially the purposesset forth. Y

@3. The improvement in the art of rolling jecting sucha body to acontinuous and proof the drawings the flanges of the respective gressiverolling and` compressive pressure tubes or roundbodies, which consistsin sub-v lili periphery from surfaces moving while moving forward in asuitable ss, to

subjecting Athe cross sections of 'the circumferential confining andlongitudinal rolling pressure varound .a large part of its4substantially longitudinally of the pass with little metal flows and-elongates in an axial fdirec- ,tion and simultaneously lsubjecting thecross sections vof 'the bodyin the exit portion "of the' same pass torollin pressure between approximately plane sur' aces movingtra'nsversely to the ass and tend-ing to rota-te the body, the said)metal bei-n supported internally upon a Asubstantial y ihard mandrel forsubstantially 'the ,purposes vset forth.

4. 'lllhe improvement :in VNthe art of 'rolling tubes or round bodies,which xconsists in s bjecting suchbody to a continuous and o- Aapproximately plane sur 5. The improvement in the art of rollingv tubesor round bodies, which consists in subjectmg such a body toa contlnuousand progresslve rolling and lcompressive presJ sure lwhile movingforward in a suitablev pass, by subjecting the cross sections of thebody to circumferential confining and longitudinal rolling pressurearound a large part of its eripherv from surfaces moving substantia lylongitudinally of the pass with little or no cross rolling motion,whereby the metal flows and elongates in an arial ydirection andsimultaneously subjecting. the crosssections of the body `1n .the exitportion of the same pass to rollin pressure between approximatelyplanesur aces moving transversely to the pass and tending to rotate thevbody, and supporting the body internally during the latter actlon upon amandrel \that is held against axial motion as the metal moves over 1t.

' 6. 'The improvement in the art of longitudinally rolling tubes orround bodies,

characterized by subjectin each advancin' -cross section to longitudinalrolling an lcircumferential 'compression throughout a largevportion-of'the lperipher and. then rol ing the bodn by pressure etween opposingcross .ro ing surfaces havin relativelyA narrow limits of contact with.the

body, the said successive treatments occuror no cross rolling motion,whereby the 'tudinally ro faces for longitudinally progressively' and incontinuitupon hettlody, for substantially'the purpbses set 7. The imrovement inthe art of "longitudinally ro ling tubes Vor round bodies,characterized 4Vby first cross rol-ling the body between surfaces havingnarrow lines or arcas lof `Contact with 'the body and rotating the body,then subjectin each advancing cross section to llongitu inal rolling andcircumferential compression throughout a lar e portion -of 'theperiphery, and then rol ing the bod H by pressure between opposing crossroling surfaces havin -relatively narrow limits -of contact wlth thebody, the said successive treatments occuring -pro ressively and incontinuity 'upon the body, '-or substantially the -purposes set forth. A

-8. The im rovement in the art of longi- Elling tubes or round bodies,characterized by first-cross rolling vthebody between surfaces bothtending to twist or rotate in a like direction, then rolling itlongitudinally, and then cross rolling -it fbetween isurfaces tending totwist or rotate it ina llike direction to eachother but reverse to thefirst said direction, for substantially the purposes set forth. Y

'9. The improvement in the art of rolling `tubes .or round bodies,characterized by first cross rolling Ithe body between rol-ls 'having'surfaces `tending Eto twist or .rotate it in a like xtiirec'tion andxthen in the same pass be-A tween the same rolls cross rolling itsadvanced portions between surfaces tending to twist or rotate in adirection reverse to the first said direction, whilecontinuing the firstcross rolling on other portions, for substantially the purposes setforth. 10. Machine for reducing metal comprismg a set of rotary membersarran ed to form a single pass, at least one of sai members having acentral portion and an outer flange portion, said central portion being11o constructed and arran ed to grip the billet circumferentially to einate it and roll it substantially lon itudina y, and said flange portionbeing inc ined to the axis of the pass erate transversely upon and crossroll the blank as it passes from the central portion, for substantiallythe purposes set forth.

1l. Rolls forming a pass and having surfaces for longitudinall rollingand circumferentially confining tide body being rolled and havingopposed surfaces in the same pass for cross rolling the body, the actingsurfaces of the rolls being convergent at the mouth ofthe pass. i 12.Rolls forming a pass and having surrolling and circume body being'rolled, surfaces for cross-rollferentially connin t and havin op ose ingIthe bo y, t e acting surfaces oft-he rolls 13o being convergent at themouth of the pass, in combination with a mandrel for internallysupporting the body at the Vpoints of longitu mal and of cross rolling.

13. Rolls forming a ass and having surfaces for longitudinal y rollinwhile circumferentially confining the ody being rolled and opposedsurfaces for cross-rolling the body, the acting surfaces of the rollsbeing convergent at the mouthof the pass, in combination .with a mandrelsupported tol'otate Without traveling in respect to the ro s.

14. `Rolling mechanism comprising rolls forming a pass and havinginclined axes for imparting endwise and rotary motions to a blank Whilegripped thereby longitudinally and circumferentlally, each of the saidrolls having a concave central portion for circumferentially confiningand longitudinally rolling the body, and a flange for crossrollin thebody, and imparting rotation, for su stantially the purposes set forth.

15. 'Rolling mechanism comprising rotary rolls forming a pass, forimparting endwise and rotary motions to a blank While grippedv therebylongitudinally and circumferentially, each of the said rolls having aconcave central ortion for circumferentially confining and).`longitudinally rolling the body, and a flange for cross rolling thebody and imparting rotation, the flanges of the rolls converging at themouth of the pass.

16. In combination, a plurality of pairs of flanges for rotatin or crossrolling the said.

body or blank an a coperating mandrel of length to extend simultaneouslyinto a plurality of the passes, at least one of which lhas such crossrolling flanges.

17. In combination, a pair of rolls forming a pass, the axis of eachroll beingv perpendicular o'r nearly so to the pass axis, the

rolls rotating in opposite dircctlons and having opposed overla pedflanges making contact with the vwor piece along longitudinally disposedlines at the exit end of the pass, for reducing cross rolling in likedirections, t e opposing faces of the flanges of the rolls convergin atthe entrance end of the pass, substantia ly as set forth.

, 18. Rolling members formin a pass and having axes inclined to each ot1er and each having a circumferentally confining and longitudinallyrolling surface portion and a cross rolling flange portion that makesacting contact against the work piece on lines disposedy along the pass.

In testimony whereof -I have signed this specification in-the presenceof two subscribing Witnesses, May 21, 1908.

RALPH CHARLES sfrIEEEL.

Witnesses:

R. T. BROWN, VLESLIE H. MANN.

